5.2 is now stack based and supports "open queries", you just miss of the '?'. So what this means is you can have TMS over reactive derivation queries. If I have a key in an envelop on a desk in an office I can add a TMS justifcation that will only exist while the key remains in the office.

This should have some very interesting use cases and I look forward to seeing what people come up with. For instance you could create a rule to monitor a project's maven dependencies and transititive depdencies and receive an alert if ASL/MIT/BSD project has a GPL dependency added via a transititive dependency.